<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <div></div>
  <script>
    const spec = { size: '40cm*40cm', color: '黑色' }
    // 1. 所有的属性值回去过来

    // const res = Object.values(spec)
    // document.querySelector('div').innerHTML = res.join('/')

    // 一步到位
    document.querySelector('div').innerHTML = Object.values(spec).join('/')
    // 2. 转换为字符串
  </script>
</body>

</html>